In recent years rationalization has advanced in every field, and, in the field of scales and other weighing devices as well, there has been a demand for faster, more accurate weighing devices.
For example, the decision on whether or not to purchase new weighing devices is determined by the merits of the purchase. In other words the decision to purchase depends upon how much processing time will be saved by the new devices and how much of the waste caused by allowances of excessive amounts due to the insufficient precision of existing weighing devices can be eliminated by the new devices.
Small-capacity scales utilizing the prior art common load cell methods use a mechanism called a "parallelogram". They are also equipped both with oil dampers to attenuate oscillation and with an analog-type higher-order filter before or after the amplifier in order to attenuate any harmful oscillation.
In a scale employing the common load cell method it is not possible to sufficiently attenuate the oscillation outputs from associated mechanical devices using only oil dampers. Therefore, the filter mentioned above must be a low-frequency range, low-pass filter with a cut-off frequency of approximately several hertz which is capable of functioning effectively to attenuate the oscillating output caused by the mechanical devices of the scale.
However, when this type of low-frequency range, low-pass filter with a cut-off frequency of approximately several hertz is used, the signal response during measurement is subjected to considerable delay, and, for practical purposes, there are limits with respect to the amount that the measurement time can be shortened.
Some weighing devices integrate the output signal from a load cell, etc., and divide this integral by the time span (also called the "interval") of the integration in order to obtain a primary estimate of the weight of the material being weighed.
Thus, the weighing methods described above increase in accuracy each time the processing operations, including the integrations, are repeated. However, in order to obtain a high degree of accuracy, it is necessary to repeat the processing operations, including the integrations. This results in a longer measurement time (processing time), thus making this method unsuitable for the high-speed weighing processing which is necessary in the "fight against the clock" so prevalent today.